Control means for power operated fastener



Aug- 97 P. WILSON ,523

CONTROL MEANS FUR POWER OPERATED FASTENER Filed Jan. 9, 1968 2 Sheets-Sheet l S r'-+- 3 44 v =3 /40 Q ii j INVENTOR P/evae WILSON ATTORNEYS Aug. 11, 1970 P. wlLso CONTROL MEANS FOR POWER OPERATED FASTENER Z Sheets-Sheet 2 PRYCE WILSON ATTORNEYS Filed Jan. 9, 1968 W wm 1 mm in u United States Patent Office 3,523,633 Patented Aug. 11, 1970 3,523,633 CONTROL MEANS FOR POWER OPERATED FASTENER Pryce Wilson, Box 684, Gal't, Calif. 95632 Filed Jan. 9, 1968, Ser."No. 696,605 Int. Cl. B27f 7/06 US. Cl. 227-7 Claims ABSTRACT OF THE DISCLOSURE Control means for a power-operated fastener driver comprising a rail, means for slidably suspending the driver from the rail, a motor for advancing the suspension means along the rail, and electrically operated means such as a switch or photoelectric cell which travels with the suspension means and is actuated by indicia spaced along the track or workpiece to close a circuit actuating the fastener driver.

Conventional pneumatically operated staplers, tackers and the like. which comprise apparatus for driving a fastener into a surface whenever a trigger is actuated, are well known. My invention is directed to means for automatically actuating the triggers of such machines, so that the fasteners may be driven at any desired points along a desired path, at any desired intervals, or at irregular intervals, without manually actuating the trigger each time a fastener is to be driven. This apparatus is responsive to the location of indicia positioned along a track Or along the surface of a workpiece into which fasteners are to be driven.

While there are a few' known fastening machines in which the trigger is automatically actuated, such as the one described in US. Pat. No. 2,915,714, in those machines-the fasteners are driven at regular intervals, and are not responsive to indicia outside the machine itself.

A preferred embodiment of my invention and two modifications thereof, will now be described with reference to the accompanying drawings, in which:

FIG. 1 is an end view of my control apparatus, with a suitable fastener driving device shown in phantom lines;

FIG. 2 is a side view thereof, with only a portion of the fastening device shown;

FIG. 3 is atop plan view;

FIG. 4 is a detail view showing an attachment comprising a detector switch which may contact the workpiece surface;

FIG. 5 shows a photocell responsive detector switch; and

FIG. 6 is a circuit diagram showing the electrical connections.

Like reference numerals denote like parts throughout the several views.

Referring now to FIG. 1, it will be seen that a fasteningdevice 10, shown in phantom lines, is fastened, through a distance piece 10a, by any suitable means, such as screws 11, to a bar 12 carried by a frame 13 which is vertically slidable within a casing 14. The casing 14 is suspended from a channel member 15, the arms 16 of which slide on a horizontal track 17. This sliding motion may be facilitated by ball bearings 18 and roller bearings 19. Alternatively, the arms 16 could be entirely vertical and rollers journalled on axes pasing therethrough could ride on the upper and lower surfaces of the track 17. The frame 13 may be suspended from the channel member by springs 20 for movement within said casing between a raised position and a lowered position, with the limits of its path of travel dependent on the position of studs 21 carried by the casing 14 which project into slots 22 in the frame 13. The springs 20 normally retain the frame and fastener in their raised position, and the frame is lowered by the solenoid 23 attached to the casing 14 by brackets 24. The movable core of this solenoid is pivotally connected at 25 to a rod 26 which actuates linkage 27 fastened at 28 to the bar 12 on the frame 13, and carrying a brake shoe 29 which projects through a hole 30 in the channel member 15 to engage the bottom of the track 17 whenever the frame and fastener are lowered.

Lowering of the frame 13 also causes a surface 3111 on the frame to close a microswitch 31 thereby actuating solenoid 32, which actuates the trigger 33 of the fastening device, thus causing it to drive a staple or the like.

Turning now to FIG. 2, it will be seen that the upper arm 34 of the track 17 carries a reversible motor 35 which drives a chain 36 mounted on sprockets 37 and attached at each end to a carriage 38. Movable cams 39 are mounted on the arm 34 of track 17. The carriage 38 carries a detector switch comprising a contact arm 40 mounted to swing about a fulcrum 41, and a fixed contact 42. The carriage also carries follower 43 having at its upper end a roller 44 for contacting the cams 39. This follower is fastened to the carrier by a spring 45 which biasses it upwardly against the cams. Whenever a cam forces the follower down, it swings the contact arm 40 about its fulcrum, thereby closing a circuit through contact arm 40 and fixed contact 42 which energizes the solenoid 23 to lower the frame and fastener. The carriage is supported on a bar 46 which is slidably carried by brackets 47 fastened to the channel member 15. Movement of the bar 46 relative to the brackets 47 is resisted by the springs 48. The ends of the bar 46 are fastened to the chain 36.

It is believed that the operation of the device will now be obvious. Whenever the motor is started, the carriage 38, and channel member 15, together with the housing, frame and fastener depending therefrom, are advanced along the track 17. When the follower 43 strikes a cam 39, the contacts 40-42 are closed, thus energizing the solenoid 23. This actuates the rod 26 and the linkage 27, simultaneously lowering the frame and fastener, while driving the brake shoe against the bottom of the track to prevent further movement of the channel member, frame and fastener along the track. This may be done without stopping the motor, because of the give in the springs 48, since the carriage 38 will simply continue on its Way, compressing one of the springs, while the channel member remains stationary. As the frame 13 descends, the surface 31a closes the microswitch 31, energizing the solenoid 32, which actuates the trigger 33, thus causing the fastening device to drive a staple or the like into the surface therebelow. As soon as the follower 43 is carried past the cam 39 the contacts 4042 are opened, thus de-energizing solenoid 23, so that the springs 20 may raise the frame 13 into its original position. As the surface 31a is lifted away from the microswitch 31, that switch returns to its open position, to which it is spring biassed, thus de-energizing the solenoid 32, and de-activating the trigger 33, until the follower reaches another stop, at which the entire cycle is repeated.

Since the motor 35 is stationary, it can easily be supplied by connecting it to any convenient source of electric power.

The solenoid 23 draws relatively little current, since the springs 20 barely counteract the force of gravity, and solenoid 32 need only actuate a trigger. The two may therefore be easily supplied by a small battery 50, carried on the casing, or through flexible wiring connected to a stationary power source. The electrical connections are shown in FIG. 6.

It will be appreciated that the switch comprising the contacts 40, 42 need not be mounted on the carrier to cooperate with stops on the track. It may instead be mounted on a projection from the bottom of the casing. In

this embodiment, illustrated in FIG. 4, a follower 43a swings a movable contact arm 40a into contact with a stationary contact 42a, whenever it encounters a ridge (or, if preferred, a depression) in the surface over which the fastening device is travelling. The fastening device may be triggered exactly when, just before, or just after the ridge or depression is encountered, depending on the relative positions of the follower and driving means with respect to the path of travel. This embodiment is particularly advantageous when the surface consists of a plurality of lapping strips to be fastened to a cross-member. The follower can be designed to detect the grooves between the strips, or raised edges due to the overlaps, so as to drive a fastener exactly where required, even though the strips differ in width so that a machine driving the fasteners at regular intervals would be unsatisfactory.

The detector switch may also be arranged, as shown in FIG. 5, to be operated by a photocell 51 instead of a follower, so as to respond to flat markings on the workpiece surface rather than to ridges or depressions. The photocell may, for example, be responsive to reflected light, to a luminescent marking; or to a particular color.

If the weight of the fastening device is not evenly distributed about the axis of the casing, spring 52 may be connected between the top of the casing and one end of the machine to offset the resulting imbalance, so that the frame will slide freely in the casing.

It will of course be appreciated that the specific embodiments hereinbefore described merely illustrate the basic principles of the invention, the scope of which is defined by the following claims.

What I claim is:

1. Control means for a power actuated fastener driver, said control means comprising a rail, fastener suspension means movably mounted on said rail, drive means for advancing said fastener suspension means along said rail, electrically operated driver actuating means carried connected to said suspension means, electrical circuit means for connecting said actuating means to a power source, circuit closing means carried by said suspension means, said circuit closing means being operative to close said circuit and thereby energize said actuating means in response to the presence of indicia adjacent the path of travel of said suspension means along said rail, means for preventing the advance of said suspension means along said rail while said actuating means is energized, and a yielding connection between said suspension means and drive means which permits continued advance by said drive means while the advance of said suspension means is being prevented.

2. Control means as claimed in claim 1 in which said rail carries said indicia.

3. Control means as claimed in claim 1 in which said indicia are cams carried by said rail and said circuit closing means comprises a main switch having a movable contact arm positioned to successively encounter and be moved by said cams as said suspension means travels along said rail.

4. Control means as claimed in claim 3 comprising driver-holding means mounted for vertical sliding movement in said suspension means, means for vertically reciprocating said driver holding means in said suspension means, and additional switch means actuated by descent of said driver holding means, said driver reciprocating means being connected to be actuated closing of said main switch, and said additional switch means being positioned in said circuit so that closing thereof energizes said actuating means.

5. Control means as claimed in claim 1 in which said circuit closing means comprises a photocell mounted on said suspension means.

References Cited UNITED STATES PATENTS 3,026,519 3/1962 Johnson 2272 3,261,527 7/1966 Sterner 227--7 3,265,274 8/1966 Burnell 227-7 GRANVILLE Y. CUSTER, 1a., Primary Examiner 

